Undercutting tool for commutators



Aug. 14, 1928. 1,680,835

. E. O. ADKINS UNDERCUTTING 'JEOOL FOR COMMUTATOHS OriginQ FiledMarch'lo, 1926 3 Sheets-Sheet l innunImuumuulnull gnmzntoi WH'nes e6 Md.2m

Aug. 14, 1928. 1,680,835

r E. o. ADKINS UNDERCUTTI ING TOOL FOR COMMUTATORS Original File'd March10, 1926 3 Sheets-Sheet 2 gmenio'a Aug. 14, 1928. l ,680,835

- E. O. ADKINS UNDERCUTTING TOOL FOR COMMUTATORS Original Fild Marsh 10,1926 3 Sheets-Sheet 3 1 HI mulmmlllm gig Patented Aug. 14,1928.

D AT S 1,6so,s3s PATENT OFFICE.

mm o. ADKINS, or nui'rrnqo'ron, wnsr wiser ma, assrenon OEONlzl-HALF r0THE nun'rnwo'ronauro SUPPLY COMPANY, OFHUNTINGTON, WEST VIRGINIA, A son,

PORATION or war vnaenna i UR'DIE}RCUTTING TOOL r03 COMMUTATORS.

This invention appertains to a novel device for undercuttmg the micaspacing enga ing the commutator comprising a stri s with novel meansassociatedlwith the device for holdingthe same in place rela tive to thecommutator.

In the use of generators and motorsthe V segments become worn leavingthe spacing I strips generally formed of mica protruding beyond, theperi hery of the commutator which causes di culty familiar with allusers ofsuchap liances.

Various meth s havebeen proposed for dressing thecommutator and forundercutting the mica strips which methods have failed to isfaction. l t

It is therefore another 1 object to provide an. undercutting toolwhichcan be readily associated with all sizes of generators and motors andmakes thereof irrespective of .the length of the commutator, thetoolembodying a novel supporting frame for engaging the commutator andanovel swinging frame carryin the dressing or undercutting wheel or thesaid strips. I 7 1 A further object of .theinvention is to provide novelmeans for' connecting the swinging frame with the supporting frame toolfor the micafspacing strips of a comsmall .cost.

mutator of the above'character, which will be durableand eflicient inuse, one that will be simple and'easy to manufacture,and one whichcan'be placed upon the market at" a undercutting wheel for the mica givethe maximum amount or sat-' stroke to permit the 1 use Application flledltarch 10, 1926, Serial No. 93,815. Renewed June 20 1927.

With these and other, objects in view, the inventlon cons sts 1n thenovel construction, arrangement and formation of parts, as will behereinafter more specifically described, 5

ing drawings, in which drawings:

Figure 1 is aside elevation of the improved tool showing the same, infull lines,

claimed,and illustrated .in the accompanyin a position of rest 'on'acommutator, and

inoperative position, in dotted lines Figure 2 is a top plan view of theimproved tool, I

Figure 3 is a front elevation of the tool, Figure 4 is a fragmentaryinner side elevation of the swinging frame showing the novelundercutting wheel,

Figure 5' is a detail section'taken on the line 55 of Figure 1illustratingthe novel means of adjust-ably associating the rest with thesupporting frame, "and Figure 6 is a detail-section takenCon the line66'0f Figure 2 illustrating themeans of detachably connecting theundercutting wheel with the drive shaft,

Figure 7 is a side] elevation of the tool showing a slightly modifiedformthereof.

Referring to the drawings in, detail, whereln -s1m1lar referencecharacters designate the corresponding views, the letter A generallyindicatesthe improved portable tool which comprises a supporting frameB,

a swingin frame C, and a drive means D for the undercutting wheel Thesupporting frame B comprises inner and outer plates 10 and 11 which areheld in spaced relation by a handle 12. The handle 12extends above theplates and is provided with a suitable hand grip 13, they purpose ofwhich will be hereinafter'more fully described. The outer plate 11-' isof I a substantially frusto-triangi'ilarshapeand has its base portionextendedbelow the inner-plate 10, which base portion is adapted to*restdirectly upon the commutator in-- dicated by the reference character F.The

commutator F can be considered of any desired construction including"the usual' copper segments 15 and mica spacing strips 14.. Thesegments15 at one end are provided with the usual risers 16. The plate11 can be providedwith suitable apertures so as to lightenthe weightthereof. The

forward edge ofthe inner plate 10has adjustably associated therewith therest 17 which embodies adjustable, legs 18, and 19. The leg 18fis of asubstantially U-shape in cross section and is slidably mounted upon thesaid plate 10, the flanges of the leg engaging the opposite faces of theplate. The lower end of the leg projects forwardly from the plate and isprovided with a foot 20 which is arranged substantially ina horizontalplane .for engaging the outer edge of the riserslb'. A slot;21 is formedin the plate 10 adjacent to and parallel with the front edge thereofanda suitable bolt is extended through the slot, and the U- shaped leg forholding :theJleg in up its ad-i j usted, position. The. belt isgenerally indice-ted by the reference. a character 22.! The leg 19gradually tapers toward a ipointfor motor 31-. 'llhese'ipulley wheelsare connectrestingfagainst the inner face ofthe risers 16 and thelegmormally rests uponone side face of the leg 18 and is provided with alongitudinally extending slot 23 through which the bolt 22 extends; Bythis arrangcment the leg 19 can be adjusted in-" dependently of the leg18 either longitudinally thereof or forwardly or rearwardly thereof,swinging upon the bolt as an axis.- The forward edge o-fz the leg '19can be pro-,

vided with av guide flange $24 for engaging the -leg 18 and the leg 18can be notched as at 25 to permit the swinging of the leg 19 whennecessary. J a

A stop arm QG'iscarried by the plate 10 and extends in spaced pa'rallelrelation there to and forms means for limitingthe swinging movementofgthe frame G in one-'direction=asfwill be hereinafter described.

' Thev,frame C comprisesa swinging-bar- 30 having secured to one endthereof any preferred type ofelectric motor 31, as M32.- The forward endof the bar 30 carriesza; bearing sleeve 33' in which is rotatably Imounted the drive shaft34.

ed together by a suitable belt 37. As intimated the undercutting wheel Eis remov- 1 ably associated with the drive-shaft 34 and the wheel isprovided with an axially e7stend-v ting shank 38 which is connected withvthe shaft 234 by any preferred, typeof socket 39 clearly shown inFigurefG of thedrawings.

This allows different sizes and types- 0f wheels to be used with thetool. As shown the wheel E, includes radially extending cub ting. teeth40 for operating on the mica strips 15. r The lower "face of the framebar 30 ladjacentrto the end thereof whichsupports the motor D hassecured thereto any preferred type-of hand grip 41'.

The means of associating,- the swingingframe C withv thesupportingifram'eB forms one of the important features of the invencentto the rear, edgethercof and at its lower end, the same is connected bymeans of a pivot boltAA with the frame bar 30 at a point intermediatethe ends thereof. Thus the swinging frame is conncctedby two pivotpoints with the supporting frame.

In use of the improved tool :thefoot-ZO is placed on the uppersurfaceofthe: riser:

16 of the ,-com mutator and the lower edge of the plate llris laiddirectly on the commutator-parallel with the mica-strips; Thev foot isadjusted relative toethe hei'ght ofthe risers andthe leg 119.;isalsoadjusted so as to iengage'the front-face ofthe risers. The

tool is now ready for opcration and current is allowed to rflowythroughthe motor by any suitabletype of control means which will bring aboutthe; rotationof-the wheeldO. The right hand ofthe user is preferablyaround the handle 41, while theleft-hand is about the hand grip 13-toform means for steadying the supporting frame. By swinging-the frame G"the wheel isbrought 'into engagement with the mica strips'15 and thewheel is moved along said'strips paralleltherewith, bringing about theundercutting] thereof. By guiding the frame G the wheel 40 can "be heldin icontactlwith the mica strip with the same pressure during-the entiremovement ofthe wheel. ,v Theframe resting upon thecommutator relievestheweight of thedevice from the usemand insures the easy manipulation ofthe tool. In some instances where the commutator is; of relatively greatsize and the risers extend la relatively great distance-beyond theperipheryof the commutator the leg18'can'be entirelyiremovedqand v theleg 19 only useda In thisicontingency the leg $19 is adjusted so astorrest ilpoh the commutator directly in front :of, the riser. 1

lll)

While-I have shown pulley wheels. and a u pulley :beltufor connectingthe armature shaft 1 ofthe motor 31 with ."the driveshaft 341 it is tobe understood :that any other suitable means can be employed forconnecting the shafts together suchi as sprocket wheels and a"silentsprocket chain, orin some instances the stop'26 which holds'theframe in a substantiallyhorizontalposition. i

Owing to the portability :of the"too1, the

same will be found especially advantageous i j for v -use m;.con unet1onwith mining ma-.

chinery asthe tool ean lie-brought directly into-the mine'eliminatin'gthe necessity. of dismantling the machinery. In actualpraotice the commutator can be acted upon by thev tool by simpl removingone of the brushes and brush holders.

In some types of tools, especially those types which are to be used inconjunction with extraordinaryilarge armatures,'the motor can be secureddirectly to the supporting frame B above the swinging frame C, as shownin Figure 7 of the drawings; In this forma-fiexible drive shaft 50 isutilized for connecting the armature shaft of the motor with the driveshaft 34. .Asshown in this figure the 'handle4l in such instance issecured to the upper surface of the frame bar30. v

Changes in details may be made without departing from the spirit or thescope of this invention, but

What I claim as new is:

1. A portable tool for undercutting the mica strips of commutatorscomprising a su porting frame for engaging and rest ng soEaly upon thecommutator, a swinging frame carried by the supporting frame, anoperating motor, a drive shaft rotatably carried by the swinging frameand operated from said motor,a rotary tool secured to the shaft forengaging the mica strips and a manipulating handle secured to theswing-' ing frame.

2. A portable tool for undercutting the mica strips of commutatorscomprising a supporting frame for resting directly and solely upon saidcommutators, a swing ng frame, an operating shaft rotatably carr ed bythe frame, a tool secured to the dr ve shaft for acting upon the micastrips, a drive motor for operating said drive shaft, and meansconnecting the swinging frame to the supporting frame whereby theIl:11C8, StI1p operating tool can be moved longitudinally of the stripin parallel relation thereto throu bout the entire length thereof.

3. 5 portable tool for undercutting the mica strips of commutatorscomprising a supporting frame including a plate for resting directlyupon the commutator and an adjustable leg for engaging a riser of one ofthe commutator segments, a swinging frame carried b and arrangedlaterally of the supporting rame, a drive motor, a drive shaft rotatablycarried by the swlnging frame, means operatively connecting the motorwith the drive shaft, an undercutting wheel detachably connected withthe shaft, and manipulating handles secured respectively to thesupporting frame and swinging frame.

4. A portable tool for undercutting the mica strips of commutatorscomprising a supporting frame including inner and outer spaced lates,the outer plate being of a greater ength than the inner plate andextending below the same for resting directly upon the commutator inparallel relation with the mica strips, an adjustable support inglegcarried by thein'ner plate for engaging a riser of one of thesegments of the with the supporting frame, whereby the frame bar can bemoved in parallel relation to the commutator at all times, means carriedby the supporting frame for engaging the commutator, a drive motor, aI'Otitt. able mica strip cutting tool rotatably carried by the swingingframe, means operatively connecting the motor with the cutting tool, anda manipulating handle secured to r the frame bar.

6. A portable tool for undercutting the insulating strips of acommutatoreomprising a supporting frame including inner and outer spacedplates, the outer plate extending below the inner plate for restingdirectly upon the commutator, an adjustable leg secured to the innerplate, a foot upon said leg for resting upon the riser of thecommutator, a second leg adjustably associated with the supporting frameand movable independently of the first leg for engaging the inner faceof the riser and the periphery of the commutator, a swingingframe, arotatable drive shaft carried by the swinging frame, a cutting wheeldetachably associ-' ated with the shaft, a drive motor, meansoperatively connecting the motor with the drive shaft, a manipulatinghandle secured to the swinging frame, and means pivotally connecting theswinging frame with the supporting frame.

7. A portable tool for undercutting the mica strips of commutator-scomprising a supporting frame including an outer plate for-restingdirectly upon the commutator, and an adjustable leg for engaging thecommutator at a point spaced from said plate,

a steadying handle secured to the supporting frame, aswinging frameincluding a frame bar, a manipulating handle secured to the frame bar, adrive shaft rotatably carried by the forward end of the frame bar, adrive motor, means operatively connecting the motor with the driveshaft, a cutting wheel detachably connected with the drive shaft, and alink pivotally connected to the frame bar at a point intermediate theends of the frame bar and, to the supporting frame at a point above saidframe bar. l

8. A portable tool for undercutting mice strips of vacommutator'comprising' a supporting frame including inner and outerspaced plateserrangedin parallel relation,

at hand grip secured to said plates, the outer plate extending below theinner plate for resting directly upon the commutator, ad-

" justablelegs earriedby: the inner plate for engaging the commutator atapoint spaced from the outer plate, aswinging frame including ahorizontally disposed frame bar, an operating shaft rotatably carried bythe forwerdendtofthe. frame; bar, a cutting tool carried by saidsh'aft,wa drivemotor secured to the rear .end of the .frame bar, meansopenatively connecting the motor with the drive shaft, amanipulatingliandle'secured tothe frame bar, a link, means pivotally securing theupper end of the link to the inner plate, means pivotally securingthelower end of,

the link to the frame bar. intermediate the ELBA o. ADKINS.

